JP2000246893A - Ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and cost of an ink jet head by providing a connecting part with a flexible print cable on the rear surface of a head substrate and making a connection with a printed board through use of a sheet of flexible print cable. SOLUTION: The ink jet head comprises a drive unit 1, a liquid chamber unit 2 and a circuit unit 3. The drive unit 1 comprises a plurality of piezoelectric elements 12 arranged in two rows on an insulating head board 11, and a frame 13 boded to surround respective rows of piezoelectric elements 12. The circuit unit 3 comprises a printed board 32 mounting a head drive IC 33, and the like, connected with connecting parts (pads) formed on the rear surface of the head board 11 through a flexible print cable(FPC) 34. After being aligned with an electrode pattern on the rear surface of the head board 11, the FPC 34 is connected with through holes 43, 44 in the head board 11 by means of solder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head, and more particularly to a connection structure between a head substrate and a printed circuit board on which a driving circuit is mounted.

[0002]

2. Description of the Related Art An ink jet recording apparatus has almost no vibration and noise during recording, and is particularly easy to colorize.
In addition to a printer that outputs data from a digital processing device such as a computer, it is also used for facsimile machines, copiers, and the like. An ink jet head used in such an ink jet recording apparatus drives actuator means such as a piezoelectric element (piezo type), a heating resistor (bubble type), a diaphragm and a counter electrode (electrostatic type) according to a recording signal. In this case, an image is recorded on a recording medium by ejecting ink droplets from nozzles.

For example, as an ink jet head using a piezoelectric element, as described in Japanese Patent Application Laid-Open No. 8-142324, a plurality of stacked piezoelectric elements are joined on a head substrate and arranged in a plurality of rows. At the same time, a frame member located around the piezoelectric element is joined, a diaphragm having a diaphragm is laminated on the piezoelectric element and the frame member, and a diaphragm is formed on the diaphragm by a laminated piezoelectric element. A pressurized liquid chamber that is pressurized through the liquid chamber and a liquid chamber partition member that forms an ink supply path that supplies ink to the liquid chamber are stacked, and a nozzle plate having a nozzle formed on the liquid chamber partition member is further stacked. There is an apparatus in which an ink droplet is ejected from a nozzle by a displacement of a laminated piezoelectric element in a direction d33.

In order to drive an ink-jet head using the displacement of the laminated piezoelectric element in the direction d33, the end electrodes on both end faces where the internal electrodes of the laminated piezoelectric element are alternately connected, and the driving required for the laminated piezoelectric element are performed. In order to apply a waveform, it is necessary to electrically connect a printed circuit board (hereinafter, referred to as “PCB”) on which a driver (drive IC) is mounted.

Therefore, for example, in the ink-jet head described in the above-mentioned publication, a common electrode pattern and individual electrode (selection electrode) patterns are formed on the surface of a head substrate on which a multilayer piezoelectric element is fixed, and the multilayer piezoelectric element and each electrode are formed. The pattern is electrically connected with a conductive adhesive or the like, and a flexible printed cable (hereinafter, referred to as “FPC”) is soldered to each electrode pattern on the substrate.
By connecting C to a PCB on which a driver is mounted, electrical connection is established.

[0006]

However, when an electrode pattern is formed on a head substrate as in the case of the above-described ink-jet head and the FPC is connected to the multilayer piezoelectric element as the actuator means, the head substrate is required to be electrically connected. Since an electrode pattern (connection portion with FPC) was formed on the surface (front surface) on the piezoelectric element side and connection with FPC was performed,
This requires an area for securing a connection portion on the head substrate, which is disadvantageous in reducing the size of the ink jet head.

[0007] Further, since the assembling must be performed while bending the FPC cable, the number of assembling steps is complicated and the cost is increased. Further, in forming an electrode pattern, it is difficult to arrange, for example, three or more rows of piezoelectric elements as actuator means on the same head substrate.

The present invention has been made in view of the above points, and has as its object to provide a small and low-cost ink jet head.

[0009]

According to a first aspect of the present invention, there is provided an ink jet head comprising: a head substrate provided with a plurality of actuators; and a circuit for selectively driving the plurality of actuators. In an inkjet head in which a printed circuit board on which a printed circuit board is mounted is connected via a flexible printed cable, a connection portion with the flexible printed cable is provided on the back surface of the head substrate, and the printed circuit board is connected to the printed circuit board with one flexible printed cable. And

According to a second aspect of the present invention, in the inkjet head according to the first aspect, the flexible printed cable is provided on the opposite side of the head substrate.
It was configured to be drawn out from the side.

According to a third aspect of the present invention, in the inkjet head of the second aspect, each of the flexible print cables has a length sufficient to twist by approximately 90 ° in a state where the flexible print cables are connected to the head substrate.

According to a fourth aspect of the present invention, in the inkjet head of the first aspect, the flexible print cable is drawn out from one side of the head substrate.

According to a fifth aspect of the present invention, there is provided the ink jet head according to any one of the first to fourth aspects, wherein the flexible print cable is provided with a slit.

According to a sixth aspect of the present invention, there is provided an ink jet head comprising: a head substrate provided with a plurality of actuators; and a printed circuit board mounted with a circuit for selectively driving the plurality of actuators, via a flexible printed cable. In the connected inkjet head,
A connection portion with the flexible printed cable was provided on the back surface of the head substrate, and a plurality of flexible printed cables were pulled out in the same direction and connected to the printed substrate.

According to a seventh aspect of the present invention, in the inkjet head of the sixth aspect, the plurality of flexible print cables are connected such that the head substrate and the printed board are connected without bending the plurality of flexible print cables. The configuration is such that the cables are connected in the order of shortest cable length.

In the ink jet head according to the present invention, a head substrate provided with a plurality of actuators and a printed circuit board mounted with a circuit for selectively driving the plurality of actuators are connected via a flexible printed cable. In the connected inkjet head,
A connection portion with the flexible printed cable was provided on the back surface of the head substrate, and the connection portion was drawn out in one direction by a flexible printed cable in which lead electrodes were laminated and connected to the printed substrate.

According to a ninth aspect of the present invention, in the ink jet head of any one of the first to eighth aspects, the flexible printed cable has a configuration in which the connection terminals of the head substrate do not protrude from the head substrate due to the resist layer.

According to a tenth aspect of the present invention, in the ink jet head of the ninth aspect, the thickness of the resist layer of the flexible printed cable does not exceed 50 μm.

An ink-jet head according to claim 11, comprising: a head substrate provided with a plurality of rows of actuator means in three or more rows; and a printed board mounted with a circuit for selectively driving the plurality of actuator means in each row. In an inkjet head connected via a flexible print cable, a connection portion with the flexible print cable is provided on the back surface of the head substrate, and the connection is made with the flexible print cable.

According to a twelfth aspect of the present invention, there is provided an ink jet head comprising: a plurality of head substrates provided with a plurality of actuators; and a printed circuit board on which a circuit for selectively driving the plurality of actuators is mounted. In the ink jet head connected through the above, a connection portion with the flexible printed cable is provided on the back surface of the head substrate, and the plurality of head substrates are connected to one flexible printed cable.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of the inkjet head according to the first embodiment of the present invention. The ink jet head includes a drive unit 1, a liquid chamber unit 2, and a circuit unit 3.

The drive unit 1 has a plurality of piezoelectric elements 12 joined in two rows on an insulating head substrate 11 made of ceramic, glass epoxy resin or the like, and the periphery of each row of the piezoelectric elements 12 is arranged. A frame 13 that surrounds and supports the liquid chamber unit 2 is joined.

On the head substrate 11, a common electrode pattern 14 for applying a drive waveform connected to one end face of the plurality of piezoelectric elements 12 and a selection signal connected to the other end face of the plurality of piezoelectric elements 12 are provided. Individual electrode pattern 1 to give
5 are provided. The common electrode pattern 14 is electrically connected to each of the pattern portions by filling a hole 15 provided in the frame 13 with a conductive adhesive.

Further, as will be described later, the head substrate 11
Are provided with through holes 43 and 44 for drawing the common electrode pattern 14 and the individual electrode pattern 15 to the back surface.

The liquid chamber unit 2 includes a vibration plate 17, a flow path forming member 18, and a nozzle plate 19 serving as a nozzle forming member.
Are laminated and thermally fused. The vibration plate 17 is formed from a diaphragm that is displaced by the piezoelectric element 12 and a base that is joined to the frame, and the diaphragm is formed from a convex portion that is joined to the piezoelectric element 12 and a thin film portion.

The flow path forming member 18 is made of a two-layer photosensitive resin film or the like, and includes the diaphragm 17 and the nozzle plate 1.
9 together with a pressurized liquid chamber 25 facing each piezoelectric element 12, a common liquid chamber 26 located on both sides of the pressurized liquid chamber 25, and a fluid resistance portion passing through the pressurized liquid chamber 25 and the common liquid chamber 26. An ink supply path 27 that also serves as an ink supply path is formed. A large number of nozzles 28 are formed on the nozzle plate 19, and a water-repellent film such as Teflon is formed on the nozzle surface so that wiping can be performed.

The circuit unit 3 includes a head driving I / O for outputting a signal for selectively driving the plurality of piezoelectric elements 12.
A printed circuit board (PCB) 32 on which C33 and the like are mounted;
It comprises a flexible printed cable (FPC) 34 for connecting the CB 32 and a connection portion (pad) formed on the back surface of the head substrate 11 of the drive unit 1.

The principle of the ink droplet ejection by the ink jet head is as follows. A print signal sent from the control unit of the recording apparatus main body is transmitted from the driving IC 33 mounted on the PCB 32 via the head substrate via the PCB 32 and the FPC 34 so as to correspond to each dot. A drive waveform is applied to the required piezoelectric element 12 from the back surface of the electrode 11 through the electrode patterns 14 and 15.

When a print signal (drive waveform) is applied, the piezoelectric element 12 is displaced in the thickness direction, the liquid chamber 25 is pressurized through the diaphragm of the vibration plate 17, and ink droplets are ejected from the nozzle 28. .

Here, the head substrate 11 of the drive unit 1 will be described including the manufacturing process with reference to FIG. First, in order to arrange the plurality of piezoelectric elements 12 on the head substrate 11, the respective electrode patterns 41 and 42 for the common electrode and the individual electrode are formed as shown in FIG. The material of these electrode patterns 41 and 42 is obtained by printing and sintering a printing material of an alloy such as Ni-Ag or Ag-Pt, but is not limited thereto.

Each of the electrode patterns 41 and 42 has a through hole 4 for electrically connecting to the back side of the head substrate 11.
3 (for common electrode) and through hole 44 (for individual electrode)
Is formed.

Then, as shown in FIG. 3B, a plate-shaped piezoelectric element 4 is formed at a predetermined position on the head substrate 11.
After bonding of the head substrate 11 and the head substrate 11 with a dicing saw or a wire saw, as shown in FIG.
The piezoelectric element 12 and the individual electrode 15 are formed by dividing the plate-like piezoelectric element 45 and the individual electrode pattern 44 by the slit groove 46 for each channel.

At this time, the through-holes 44 of the individual electrodes 15 are connected to the individual electrode patterns 15 in a one-to-one manner, whereby the individual electrodes 15 are drawn out to the back surface of the head substrate 11. As described above, the common electrode 14 is filled with a conductive adhesive in the hole 16 provided in the frame 13 to establish conduction of each pattern portion, and is drawn out to the back surface through the through hole 43 of the common electrode 14. .

Thereafter, the frame member 13 is bonded and bonded to the head substrate 11 on which the slit processing of the piezoelectric element 45 has been completed, and the drive unit 1 is completed.
And the liquid chamber unit 2 separately processed and assembled.

Thereafter, the exposed portion of the FPC 34 is plated with solder, and is aligned with the electrode pattern on the back surface of the head substrate 11 as shown by a broken line in FIG. The solder is melted and the FPC 34 and the through hole 4 of the head substrate 11 are melted.
It connects with 3 and 44 to obtain conduction. At this time, the piezoelectric element 2
Since the electrode patterns for the rows are arranged in a plane, they can be pressed at once. Also, the FPC 34
Similarly, the connection is made in the same manner as the electrode pattern of the PCB 32 (not shown, but located on the lower surface of FIG. 1) as shown by a broken line in FIG. This crimping can also be performed at once.

As described above, since the connection portion (pad) with the FPC is provided on the back surface of the head substrate, the area of the connection portion can be saved, and a small (particularly narrow) inkjet head can be obtained. Further, since the FPC can be handled in a planar manner and mounted, a plurality of rows (two rows in this embodiment) can be crimped at a time, and the assembling process can be shortened, which is advantageous in cost. In addition, since the connection portion of the electrode is on the back surface, it is possible to prevent an electrical short circuit due to ink entering from the nozzle surface.

Although not shown in this embodiment, a spacer for holding the head substrate 11 and a nozzle cover for covering the periphery of the nozzle plate may be provided as in the related art. The FPC is composed of the head substrate 11 and the PCB 3
By connecting (crimping) and folding after connection, space saving can be achieved.

Next, FIG. 3 is an exploded perspective view of an ink jet head according to a second embodiment of the present invention. This embodiment includes the same drive unit 1, liquid chamber unit 2 and circuit unit 3 as in the first embodiment, and further includes a head cover 4 and a head substrate 1 that cover the peripheral portion of the nozzle plate 19.
1 is provided. Head cover 4
The protrusion 36 and the recess 37 which engage with each other
Is formed.

A notch 38 is formed in the FPC 34 so that the pull-out direction of the FPC 34 is
Are limited to two opposite sides. This makes it possible to securely hold the head substrate 11 using the remaining two sides. That is, here, the spacer 5 and the head substrate 11
And the bonding becomes strong.

Further, the FPC3 is represented by a line as shown by a straight line 35.
4 can be folded, and space saving is facilitated. That is, in order to fold similarly in the first embodiment, it is necessary to fold it in four, but in this case, disconnection or the like is likely to occur.

Further, the connection of the FPC 34 on the back surface of the head substrate 11 has the effects of saving the connection area, shortening the pressure bonding step, preventing electrical short-circuiting due to ink, and the like. The same is true.

FIG. 4 is an exploded perspective view for explaining another example of the second embodiment of the present invention, and FIG. 5 is a perspective explanatory view for explaining the same example. In this example, the FPC 34 is drawn linearly from two opposing sides of the head substrate 11.

That is, as shown in FIG. 4, after the FPC 34 is pressure-bonded to the back surface of the head substrate 11 from the FPC 34 side (lower surface), one side of the electrode pattern of the PCB 32 and the FPC 34
Crimp from the side (lower surface). Thereafter, as shown in FIG.
Twist the CB32 to connect the terminal of the FPC34 on the opposite side to the PCB
32.

In this case, due to the heat capacity, when performing thermocompression bonding, it is necessary to press the crimping tip from the FPC 34 side. Therefore, the final connection is performed using an L-shaped crimping tip.
Crimping is performed from the inside of the ring formed by the PC 34, or by laser processing or heat flow spraying. In this embodiment, since an FPC having a small area can be used,
FPC cost can be reduced. In addition, since the FPC can be folded straight, space saving can be easily achieved.

As described above, in the second embodiment, the direction of pulling out the FPC is limited to two opposing sides of the head substrate, so that the head substrate can be securely held and the FPC is designed to be easily folded. And the size of the inkjet head can be reduced.

Next, FIG. 6 is a perspective view for explaining a third embodiment of the present invention. The head configuration of the present embodiment is the same as that of FIG. 4, but the FPC 34 has a length sufficient to twist 90 ° when connected to the head substrate 11. Thus, the crimping tip can be pressed from the direction of the arrow in FIG.
Assembling with B32 becomes easy. In addition, by connecting the FPC 34 to the back surface of the head substrate 11, it is possible to obtain the same effects as saving the connection area, shortening the pressure bonding step to the head substrate, and preventing electrical short circuit due to ink. .

FIG. 7 is a perspective view for explaining a fourth embodiment of the present invention. In the present embodiment, the FPC 34
Is drawn out from one side of the head substrate 11. That is, when the FPC 34 is connected to the back surface of the head substrate 11, the above-described effects can be obtained.
The electrode terminal surface of 34 faces outward. That is,
As shown in the example of FIG. 4 described above, if an attempt is made to connect to the PCB 32 without twisting the FPC 34, the FP is
Since it is necessary to crimp from the C34 side, it is necessary to crimp from inside the closed loop.

Therefore, the FPC 34 is mounted on the head substrate 11
By pulling out from the side, the FPC 34 and the PCB 32 are prevented from forming an arc (forming a ring). Therefore, since one direction is open, it is possible to easily perform pressure bonding from the FPC 34 side. In addition, it is costly to draw out the electrode surface of the FPC 34 to the back surface. Note that F
The same effect can be obtained by connecting the PC 34 on the back surface of the head substrate 11, such as saving the connection area, shortening the pressure bonding step to the substrate head, and preventing electrical short circuit due to ink.

Next, FIG. 8 is a perspective view for explaining one example of a fifth embodiment of the present invention, and FIG. 9 is a perspective view for explaining another example of the fifth embodiment. In the present embodiment, as shown in FIG. 8, the FP in the second embodiment shown in FIG.
C34 processed with a slit 39 is used, or as shown in FIG. 9, FP is used in the second embodiment shown in FIG.
C34 processed with a slit 39 is used.

By forming the slits 39 in the FPC 34 in this manner, stress and deformation (wrinkles) due to heat at the time of press bonding can be released, and connection can be made reliably. In addition, displacement of the electrode pattern due to dimensional error
The position can be adjusted by absorbing the light with the slit 39. It is to be noted that connecting the FPC 34 on the back surface of the head substrate 11 has the same effects as saving the connection area, shortening the pressure bonding step to the substrate head, and preventing an electrical short circuit due to ink. .

Next, FIG. 10 is an exploded perspective view for explaining a sixth embodiment of the present invention. This ink jet head is also composed of a drive unit 1, a liquid chamber unit 2 and a circuit unit 3, and the function and manufacturing method of each unit are as described in the first embodiment.
This is the same as the embodiment. In this embodiment, a plurality of FPCs 34-1 and 34-2 are pulled out in the same
Connected to CB32.

That is, as described above, when the FPC 34 is closed as described in the fourth embodiment, the PCB 32
Although it can be solved by pulling out the FPC 34 from one side of the head substrate 11 as described in the embodiment, when the inkjet resolution DPI (dot par inch) is large, FPC34
Since the electrode pattern becomes fine, it is difficult to arrange a plurality of rows together as in the embodiment.

Therefore, in this embodiment, FPCs for a plurality of columns are used.
Are connected separately and are pulled out in the same direction so that the FPC is not closed. This makes it possible to easily press-bond the FPC and the PCB. In addition,
Similarly, by connecting the FPCs 34-1 and 34-2 on the back surface of the head substrate, it is possible to obtain the same effects as saving the connection area and preventing an electrical short circuit caused by ink (using a plurality of FPCs). Therefore, the pressure bonding process to the head substrate is not shortened.) In this case, the same FP
C can be used, and the design cost of the FPC is reduced.

Next, FIG. 11 is an exploded perspective view for explaining a seventh embodiment of the present invention. In this embodiment, the FPCs 34-1 and 34-2 are connected in the order of shorter FPC length so that the FPCs 34-1 and 34-2 can be connected to the head substrate 11 and the PCB 32, respectively, without being bent.

Thus, the FPC can be pressure-bonded without bending, so that the pressure-bonding process is further facilitated. In addition, by connecting the FPC on the back surface of the head substrate 11, the same effects as saving the connection area and preventing an electrical short circuit due to ink can be obtained.

Next, FIG. 12 is an exploded perspective view for explaining an eighth embodiment of the present invention, and FIG. 13 is a sectional explanatory view of the same embodiment. In the present embodiment, the lead electrodes are drawn out in one direction by the laminated FPCs 34 and connected to the head substrate 11 and the PCB 32. That is, as shown in FIG. 11, the FPC 34 includes a base 34-10, a first electrode pattern (lead electrode) 34-11, and a resist layer 34-.
12, a second electrode pattern (lead electrode) 34-13 and a resist layer 34
-14.

Thus, the head substrate 11 and the FPC 3
4. Since the PCB 32 and the FPC 34 can be respectively pressure-bonded at one time, the assembly process is facilitated. In addition, since all the connection portions of the electrode pattern are flat, it is possible to perform all of the pressure bonding at the same time. In addition, by connecting the FPC on the back surface of the head substrate 11, the same effects as saving the connection area and preventing an electrical short circuit due to ink can be obtained.

FIG. 14 is a perspective view for explaining a ninth embodiment of the present invention, and FIG. 15 is a perspective view for explaining another example of the embodiment. In the present embodiment, the range of the resist layer (also referred to as an insulating layer or a cover layer) of the FPC 34 of the above-described eighth embodiment is limited, that is, FP
The connection terminal (lead electrode) 34-11 of C34 is provided in a range not protruding from the head substrate 11.

Specifically, as shown in FIG.
The length is increased until the resist layer 34-12 of 34-1 overlaps the head substrate 11. As a result, an electrical short circuit due to the ink can be more reliably prevented. Since the FPC 34-2 in the figure is shorter than the head substrate 11 in the connected state, it does not protrude from the head substrate 11. Further, more preferably, as shown in FIG.
A resist layer 34-12 is also provided at the end of -2.

Here, the FPC 34 (34-1, 34-
The thickness of the resist layer 34-12 in (2) is set not to exceed 50 μm. In particular, when a resist layer is superimposed on the head substrate 11 as in this embodiment, poor pressure bonding may occur due to the step due to the thick resist layer. When we experimentally investigated the thickness of the resist layer and the failure rate of pressure bonding,
There was no problem when the thickness was less than 50 μm, that is, when the thickness of the resist layer was less than 50 μm, reliable pressure bonding was possible.

FIG. 16 is an exploded perspective view of an ink jet head according to a tenth embodiment of the present invention. This ink jet head also has a drive unit 1, a liquid chamber
And the circuit unit 3, but the piezoelectric element 12
Are arranged in three rows, and correspondingly, three rows of the pressurized liquid chamber 25 and the nozzles 28 are also provided. Note that the number of rows is not limited to three.

In the rows other than the end row of the piezoelectric element rows on the head substrate 11 (the middle row in the case of three rows), one side is connected to the individual electrode 15 and the other side is connected to the common electrode 14. Must. That is, the space between the piezoelectric element rows cannot be simply filled with the conductive adhesive as in the case of two rows.

Therefore, the hole 16 formed in the frame 13 is
One of the holes 16a and 16b is moved to the end and the electrode pattern of the head substrate 11 is divided, and the individual electrodes 15 of the middle piezoelectric element row are connected to the back surface through holes. Then, FPCs 34-1, 34-2, 3
4-3 are connected.

As described above, when three or more rows of piezoelectric elements are provided on the same head substrate, the FPC cannot be connected to the electrode pattern on the surface of the head substrate as in the related art. By drawing out the connection portions of the electrodes to the back surface using the through holes as described above, it becomes possible to provide three or more rows of piezoelectric elements on the same head substrate.

Then, by connecting and laminating FPCs from the back surface of the head substrate for each row of the piezoelectric elements, the pressure bonding step can be simplified. The connection method of the FPC is not limited to this. As a result, the ink jet head can be miniaturized and integrated, the pressure bonding of the FPC to the head substrate can be simplified, the cost is advantageous, and the effects such as prevention of electrical short circuit due to ink can be obtained. .

FIG. 17 is an exploded perspective view of an ink jet head according to an eleventh embodiment of the present invention. This ink jet head has a plurality of sets of the drive unit 1 and the liquid chamber unit 2 described above, and is connected to the circuit unit 3 by one FPC. The FPC 34 is bent between the drive units 1 and further twisted by 90 ° so that the PC
B32.

Although the two driving units 1 are connected here, the FPC 34 has a repetitive shape, and even if the number of units increases, the FPC 34 can be connected by increasing the repetition of the FPC in the same manner.

As described above, the connection portion with the FPC 34 is pulled out to the back surface of the head substrate 11 and a plurality of head substrates 11
Are connected by one FPC 34, it is possible to mount them all at once. Thereby, the number of steps is reduced, which is advantageous in cost. In addition, since the electrode terminals of the head substrate are on the back surface, it is possible to obtain an operational effect such as prevention of electrical short circuit due to ink.

In each of the above embodiments, the present invention is applied to a piezo-type ink-jet head using a piezoelectric element as an actuator. However, the present invention is also applied to a bubble-type ink-jet head using a heating resistor. Alternatively, the present invention can be applied to an electrostatic ink jet head using electrostatic force between a diaphragm and an electrode facing the diaphragm.

[0070]

As described above, according to the ink jet head of the first aspect, the connection portion with the FPC is provided on the back surface of the head substrate, and the FPC is connected to the PCB by one FPC. The area of the portion can be omitted, the head can be reduced in size, and the connecting portion is arranged in a plane, so that the FPC can be pressure-bonded at one time, which is advantageous in terms of cost. Since the portion is on the back surface, it is possible to prevent an electrical short circuit due to ink entering from the nozzle surface.

According to the ink jet head of claim 2, in the ink jet head of claim 1,
Since the PC is configured to be drawn out from two opposing sides of the head substrate, it is possible to securely hold the head substrate,
Further, the FPC can be folded in a straight line, so that disconnection can be prevented and space can be saved.

According to the ink jet head of the third aspect, in the ink jet head of the second aspect, F
Since the PC was configured to have a length sufficient to twist by approximately 90 ° when connected to the head substrate, the FPC and the PPC
The press bonding of CB becomes easy, which is advantageous in terms of cost.

According to the ink jet head of claim 4, in the ink jet head of claim 1, F
Since the PC is configured to be drawn out from one side of the head substrate, the FPC does not form a ring, and the FPC can be easily press-bonded to the PCB from the FPC side, which is advantageous in terms of cost.

According to the ink jet head of the fifth aspect, in the ink jet head of any one of the first to fourth aspects, the FPC is provided with a slit, so that stress and deformation (wrinkles) due to heat can be absorbed. In addition, it is possible to reliably perform pressure bonding, and it is possible to absorb a small amount of misalignment due to a dimensional error, thereby facilitating alignment.

According to the ink jet head of the sixth aspect, a connection portion with the FPC is provided on the back surface of the head substrate,
Since a plurality of FPCs are pulled out in the same direction and connected to the PCB, the FPCs do not loop, and the PCs can be easily
B can be crimped, which is advantageous in terms of cost.

According to the ink jet head of claim 7, in the ink jet head of claim 6, the length of the plurality of FPCs is short so that the head substrate and the PCB are connected without bending the plurality of FPCs. Since they are connected in order, they can be easily pressed from the FPC side to the PCB, which is advantageous in terms of cost.

According to the ink jet head of the eighth aspect, a connection portion with the FPC is provided on the back surface of the head substrate, and the lead electrode is pulled out in one direction by the FPC on which the lead electrodes are laminated.
Since it is configured to be connected to the CB, it is possible to easily perform the crimping process and reduce the processing cost.

According to the ninth aspect of the present invention, in the ink jet head of any one of the first to eighth aspects, the FPC is configured such that the connection terminals of the head substrate do not protrude from the head substrate by the resist layer. Electrical short circuit can be prevented more reliably.

According to the ink jet head of claim 10, in the ink jet head of claim 9, F
Since the thickness of the resist layer of the PC does not exceed 50 μm, it is possible to reduce pressure-bonding failure due to a step of the resist layer.

According to the ink-jet head of the eleventh aspect, since a connecting portion with the FPC is provided on the back surface of the head substrate having a plurality of actuator means provided in three or more rows and connected to the FPC, high integration is achieved. An ink jet head can be obtained.

According to the ink jet head of the twelfth aspect, a connection portion with the FPC is provided on the back surface of the plurality of head substrates provided with the plurality of actuator means, and the plurality of head substrates are connected to one FPC. With this configuration, a highly integrated inkjet head can be obtained, and the assembling process can be simplified, which is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an inkjet head according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a manufacturing process of a drive unit of the head.

FIG. 3 is an exploded perspective view for explaining an example of a second embodiment of the present invention.

FIG. 4 is an exploded perspective view for explaining another example of the second embodiment of the present invention.

FIG. 5 is a perspective explanatory view for explaining another example.

FIG. 6 is a perspective explanatory view for explaining a third embodiment of the present invention;

FIG. 7 is an exploded perspective view for explaining a fourth embodiment of the present invention.

FIG. 8 is a perspective explanatory view for explaining an example of a fifth embodiment of the present invention;

FIG. 9 is an exemplary perspective view for explaining another example of the embodiment;

FIG. 10 is an exploded perspective view for explaining a sixth embodiment of the present invention.

FIG. 11 is an exploded perspective view for explaining a seventh embodiment of the present invention.

FIG. 12 is an exploded perspective view for explaining an eighth embodiment of the present invention.

FIG. 13 is an explanatory sectional view of the FPC of the embodiment.

FIG. 14 is an exploded perspective view for explaining an example of a ninth embodiment of the present invention;

FIG. 15 is an exemplary perspective view for explaining another example of the embodiment;

FIG. 16 is an exploded perspective view of an inkjet head according to a tenth embodiment of the present invention.

FIG. 17 is an exploded perspective view of an inkjet head according to an eleventh embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... drive unit, 2 ... liquid chamber unit, 3 ... circuit unit, 4 ... head cover, 5 ... spacer, 11 ... head board, 12 ... piezoelectric element, 32 ... PCB, 34 ... FPC.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryo Aoki 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2C057 AF34 AF70 AG14 AG44 AG82 AG84 BA04 BA14

Claims (12)

[Claims] 1. An ink jet head comprising: a head substrate provided with a plurality of actuators; and a printed circuit board on which a circuit for selectively driving the plurality of actuators is mounted via a flexible print cable. An ink jet head, wherein a connection portion with the flexible printed cable is provided on the back surface of the head substrate and connected to the printed substrate with one flexible printed cable. 2. The ink jet head according to claim 1, wherein the flexible print cable is drawn from two opposite sides of the head substrate. 3. The ink-jet head according to claim 2, wherein said flexible printed cable has a length sufficient to twist each of said flexible printed cables by approximately 90 ° when connected to said head substrate. 4. The ink jet head according to claim 1, wherein the flexible print cable is drawn from one side of the head substrate. 5. The ink jet head according to claim 1, wherein a slit is provided in the flexible print cable. 6. An inkjet head in which a head substrate provided with a plurality of actuators and a printed circuit board mounted with a circuit for selectively driving the plurality of actuators are connected via a flexible printed cable. An ink jet head, wherein a connection portion with the flexible printed cable is provided on the back surface of the head substrate, and a plurality of flexible printed cables are pulled out in the same direction and connected to the printed substrate. 7. The inkjet head according to claim 6, wherein the length of the plurality of flexible printed cables is set such that the head substrate and the printed substrate are connected without bending the plurality of flexible printed cables. An ink jet head characterized by being connected in a short order. 8. An inkjet head in which a head substrate provided with a plurality of actuators and a printed circuit board mounted with a circuit for selectively driving the plurality of actuators are connected via a flexible printed cable. An ink jet head, wherein a connection portion with the flexible printed cable is provided on the back surface of the head substrate, and is connected to the printed substrate by being pulled out in one direction by a flexible printed cable in which lead electrodes are laminated. 9. The ink jet head according to claim 1, wherein the connection terminal of the head substrate does not protrude from the head substrate due to the resist layer of the flexible print cable. 10. The ink jet head according to claim 9, wherein the thickness of the resist layer of the flexible printed cable does not exceed 50 μm. 11. A head board provided with a plurality of rows of actuator means in three or more rows, and a printed board mounted with a circuit for selectively driving the plurality of actuator means in each row, via a flexible printed cable. In the ink jet head, the connection portion with the flexible print cable is provided on the back surface of the head substrate, and the ink jet head is connected to the flexible print cable. 12. An ink in which a plurality of head substrates provided with a plurality of actuator units and a printed circuit board on which a circuit for selectively driving the plurality of actuator units are mounted via a flexible printed cable. In the jet head, a connection portion for connecting to the flexible printed cable is provided on a back surface of the head substrate, and the plurality of head substrates are connected to one flexible printed cable.